dcrdtest: Use dcrd --piperx to shutdown

This provides a cleaner shutdown procedure in windows, where the
interrupt signal is not available.

dcrdtest/node.go

@@ -49,6 +49,10 @@ type nodeConfig struct {
 	// pipeTX are the read/write ends of a pipe that is used with the
 	// --pipetx dcrd arg.
 	pipeTX ipcPipePair
+
+	// pipeRX are the read/write ends of a pipe that is used with the
+	// --piperx dcrd arg.
+	pipeRX ipcPipePair
 }
 
 // newConfig returns a newConfig with all default values.
@@ -57,6 +61,11 @@ func newConfig(prefix, certFile, keyFile string, extra []string) (*nodeConfig, e
 	if err != nil {
 		return nil, fmt.Errorf("unable to create pipe for dcrd IPC: %v", err)
 	}
+	pipeRX, err := newIPCPipePair()
+	if err != nil {
+		return nil, fmt.Errorf("unable to create pipe for dcrd IPC: %v", err)
+	}
+
 	a := &nodeConfig{
 		listen:    "127.0.0.1:0",
 		rpcListen: "127.0.0.1:0",
@@ -70,6 +79,7 @@ func newConfig(prefix, certFile, keyFile string, extra []string) (*nodeConfig, e
 		keyFile:  keyFile,
 
 		pipeTX: pipeTX,
+		pipeRX: pipeRX,
 	}
 	if err := a.setDefaults(); err != nil {
 		return nil, err
@@ -330,16 +340,23 @@ func (n *node) stop() error {
 		return nil
 	}
 
-	// Send kill command
-	n.tracef("stop send kill")
-	var err error
-	if runtime.GOOS == "windows" {
-		err = n.cmd.Process.Signal(os.Kill)
-	} else {
-		err = n.cmd.Process.Signal(os.Interrupt)
-	}
+	// Attempt a graceful dcrd shutdown by closing the pipeRX files.
+	err := n.config.pipeRX.close()
 	if err != nil {
-		n.t.Logf("stop Signal error: %v", err)
+		n.logf("Unable to close piperx ends: %v", err)
+
+		// Make a harder attempt at shutdown, by sending an interrupt
+		// signal.
+		n.tracef("stop send kill")
+		var err error
+		if runtime.GOOS == "windows" {
+			err = n.cmd.Process.Signal(os.Kill)
+		} else {
+			err = n.cmd.Process.Signal(os.Interrupt)
+		}
+		if err != nil {
+			n.t.Logf("stop Signal error: %v", err)
+		}
 	}
 
 	// Wait for pipes.

dcrdtest/node_common.go

@@ -12,11 +12,13 @@ import (
 func setOSNodeCmdOptions(n *nodeConfig, cmd *exec.Cmd) {
 	cmd.ExtraFiles = []*os.File{
 		n.pipeTX.w,
+		n.pipeRX.r,
 	}
 }
 
 // appendOSNodeArgs appends platform-specific arguments needed to run dcrd.
 func appendOSNodeArgs(n *nodeConfig, args []string) []string {
 	args = append(args, "--pipetx=3")
+	args = append(args, "--piperx=4")
 	return args
 }

dcrdtest/node_windows.go

@@ -14,12 +14,14 @@ func setOSNodeCmdOptions(n *nodeConfig, cmd *exec.Cmd) {
 	cmd.SysProcAttr = &syscall.SysProcAttr{
 		AdditionalInheritedHandles: []syscall.Handle{
 			syscall.Handle(n.pipeTX.w.Fd()),
+			syscall.Handle(n.pipeRX.r.Fd()),
 		},
 	}
 }
 
 // appendOSNodeArgs appends platform-specific arguments needed to run dcrd.
 func appendOSNodeArgs(n *nodeConfig, args []string) []string {
 	args = append(args, fmt.Sprintf("--pipetx=%d", n.pipeTX.w.Fd()))
+	args = append(args, fmt.Sprintf("--piperx=%d", n.pipeRX.r.Fd()))
 	return args
 }